280Bio Inc., a US-based clinical stage biotechnology company and a wholly owned subsidiary of Shanghai Yingli Pharmaceuticals Inc of Shanghai, China, announced on Friday that it has treated its first patient with advanced cancer harbouring mutations in KRAS, HRAS, or NRAS with TEB-17231 (YL-17231), a small molecule inhibitor of RAS signalling.

The company says that TEB-17231 demonstrated potent inhibition of tumour cell proliferation in vitro and in vivo in preclinical research, exhibiting activity with different KRAS, NRAS and HRAS alterations, including tumours that have become resistant to KRAS G12C inhibitors. This first US patient was enrolled at The University of Texas MD Anderson Cancer Center, Houston, Texas, by David Hong, MD, deputy chair of Investigational Cancer Therapeutics and lead investigator on the trial.

Michael Hui, 280Bio chief executive officer, said: "We are gratified that the first patient has been dosed with our novel pan-RAS inhibitor, marking a major step in TEB-17231's clinical development, and introducing new medicines for the patients we hope to serve. This milestone highlights our commitment to addressing unmet needs in cancers through precision oncology approaches. We look forward to continued enrolment and dosing of patients in this trial."